Forum: HoseHeads Sprint Car General Forum (go)
Moderators: dirtonly  /  dmantx  /  hosehead

OK, how about an exlanation for this semi-newcomer? Tracks don't get "rubber down" until they've been racing a while. What kind of track conditions prior to the race create "rubber down" conditions? and why?

104 views & nobody wants to enlighten me?

waaaa......

I'll do my best, although I'm hardly an expert on track prep.    When the track is "rubber down" then one of two things has happened.  There is either no more moisture coming up to the surface, or the top surface of the track has sealed up and the moisture can't get to the surface.    In the latter case that's when you'll see them tilling up the track during the show, because they think there is more moisture down there.

There are quite a few factors that will affect the track surface in the days before the race.    High winds will affect it because it makes it harder to get the needed water on the track.   A hot sun will do the same thing.  Both cause the water to evaporate before it gets down into the track.    Combine the two and that makes it much harder.     Rain can be a good thing or a bad thing depending on when it happens and how heavy it is.    If the rain prevents them from opening the track up when they need to, then the track will probably be bad.     

On race day itself it will depend on what you're running, plus the weather conditions.    Are you running 50 winged sprints with another four support classes?   Much harder to keep the track in great shape if that's the case.   That's why I like it that Devils Bowl only runs two support classes on their ASCS National shows.    Personally, I like the track just a little bit rubbery.    The Bowl is lightning fast when it's tacky, but the racing sucks.   ASCS or WoO doesn't matter, sprint car heats on a tacky Devils Bowl always look like a freight train with very little actual racing.   Lay a little rubber on the track and it slows a little, but the racing gets much better.   I don't like heavy rubber from top to bottom to where it looks like an asphalt track, but sometimes the racing is still good even on that type of surface.    Being able to guess which way the track is going early in the evening can be an advantage if you can get your car setup correctly for the feature.    My nephew (the driver) and my brother were out walking the track one night during intermission noting the light rubber on the track.  My nephew says "I think there's moisture underneath it".  Then my brother says "yeah, but you don't race underneath it!".   Hope that helps a little.   Hopefully there are some track prep geniuses here that will enlighten even further.  

Thanks Willie. Seems like its a tricky science (or art?)

Check out "Around the Track with Chris Dunkin on Knoxvilles You Tube page... It's pretty interesting.

I tried to upload it for you but couldn't!!!  

I imbedded the Dunkin video, hope it works.

From what I’ve seen at Knoxville and beyond, there are a number of things a track prep crew can control, and a number of things they can’t control.  What they can control is:  how much/how deep they dig up the dirt, how much they water it, how much they pound it with a sheep’s foot, and how long/how tight they pack it.  Things that are out of their control are:  the sun, the sun’s intensity (lack of clouds), heat, humidity, and wind.  The things they are in control of are important, but arguably the most important things (sun, wind, heat, humidity) are completely out of their control. 

Something else probably not everybody thinks of is the difference that technology makes, or has made.  The cars are faster, lighter, and have wider and softer tires than they used to (in the 80s, 90s, etc) – all with the same amount of downforce, or maybe even more.  The result of that is an increase in the abuse on the track, which dries it out, and can lead to rubber.  I’ve heard that Knoxville used to add horse manure and/or calcium chloride to the track in the 80s/90s to cut down on dust and make the dirt stickier, but had to stop that due to EPA concerns.  What time the races start, or should start, can be another important factor that is out of the immediate control of the track prep crew.

At Knoxville (and other places as well, I’m sure), rubber generally is laid when the bottom groove is completely gone and the top groove is dried up crumbs prior the A-Main.  Once the top groove is completely worn out and on the fence, rubber is laid from top to bottom.  Since the bottom is the shortest distance around a big, wide track, everybody lines up down low for the parade in the rubber.  

The Dunkins do a pretty awesome job, which is why the racing is usually as good as it is.  Even they miss it from time to time though.  Most of the time it is due to the weather, as they put in the time & effort to control the things they can control.  It’s definitely somewhat of a fine art… probably more of a weird science!  

Here is the link to the video, nonetheless:  http://www.youtube.com/watch?v=cL-dVvdqbGo

Thanks Chilly. Seems like a lot depends on whims of Mother Nature, only so much us earthlings can do. I've been to Nationals 3 times, only time racing was less than stellar was last year, Wednesday, after a brief rain track was wicked fast but not much passing. I would also guess "Mississippi gumbo" reacts differently than Pennsyltucky red clay....

Great video! I wonder if there are any complaints about dumping all that water when its drought conditions? 2 years ago that short corn was scary....

Yeah dry conditions cause a track to get rubbered up. The track dries up and becomes hard and abrasive. By then the cushion is usually gone so no one is running up top. The cars running the same bottom line causes the tires to burn rubber to the track which creates the only traction you're gonna find and the end result is a bottom-line parade. I have actually seen tracks that were so bad that the rubber was laid early in the show and widened out enough by the end of the feature to have 2 or at least 1 1/2 lanes to race on. Hagerstown comes to mind.

A

Horse manure in the 80s and 90s

Got that info from a good sorce right  

revjimk, what a great question. I've been going to sprint car races for many years, had an idea of why but, now I've a better understanding thanks to those who answerd. Thank you gentlemen. As for FORD97, YOUR A DUMP TRUCK ! No shit. Lol !

Peace, Out.

from: central coast of cali.

The only really crappy sprint car race I've seen in my brief 4 years of this stuff was at Hagerstown.  Won't go back, also have a gripe about the place cause my hero from dirt track modified racing in the 1960s, Smokey Stover of Staunton, Va., suffered career ending injuries there.

Thanks. At first I didn't think anyone would answer

Now I want to know what a "Jacob's Ladder" does, & how the drivetrain works without clutch or old fashioned "In & out box". Can the engine idle at all? Or can it be disengaged but not engaged?

I've got a pretty good idea what a Jacob's Ladder does, but I've never actually worked on a sprint car.   I'll let the sprint car mechanics and chassis experts answer those questions, and I look forward to reading any of their answers myself.   I had questions myself about how the torsion stops were causing some of these violent accidents.

Unfortunately for me, my only mechanical experience is on stock cars.    My brother's current racecar is a IMCA style sportmod, which is little more than a IMCA stock car with a modified body on it.   I don't even like that type of car, and watching them run after watching sprints is like watching paint dry.   Maybe one of these days I'll get an opportunity to wrench on a sprinter.    Ironically, with the money my brother spends on this friggin' sportmod he could probably own a 305 sprint.  

The Jacobs Ladder in short keep the rear end from moving side to side in the car.  However, there are many adjustments you can make with the "jake" to improve the cars performance.  

Drivetrain is simple as well, you are either in gear or not.  Yes the engine can idle after it is fired and the driver takes it out of gear.  For the most part once it is out of gear it does not go back in gear while running.  Although I have seen Jeff Swindell do it.

IMO, the torsion stops in question are made out of Titanium and I don't believe they are flexing around the bar enough.  So when they are tightened they simply are not "gripping" the bar.  Now the retainers they are using has fixed that issue.  Anyone else please let me know if this is inaccurate.

DA

Fact on the manure - not necessarily just horse manure as far back as the 60's. Across from the fair grounds, where Hy Vee is, there used to be a sale barn. The gentleman, Ralph Grabal - that taught the Dunckins - would bring in the manure. The idea was that it would eat up the rubber. Ralph would load up the surface in the fall mix it up with the dirt and let it sit all winter.

The jacobs ladder basically keep the rear end located laterally. As for no clutches this is why they are push started. Basically like when you pop start a manual transmission car when you pop the clutch the tires hook up and turn the motor over, only with a sprint car there is no clutch and the tires are already hooked up when the car is placed in gear this is why they slide briefly when being pushed off before they can hook up and start turning the motor over. Sprint cars can idle when they bring them into the pits to warm them up they pull the handle up and disengages the rearend you can't however engage the rearend once idling thus the need to be pushed off after stoping each time.